NOTES for Th1 4:1-12
Continuing the conversation about the life of the Kingdom, Paul draws attention to its most important feature: those called to such a life must always preserve a state of sanctification (v. 7; in the Synodal translation sanctification is usually called "holiness"). Here the apostle is obviously continuing the tradition formed back in the times when the second part of the Book of Leviticus was written (Lev 19-27): it is precisely here that the call first sounded not simply to purity, which had sounded before, but to a sanctified life (Lev 1-2).
Paul also calls the addressees of his letter to a sanctified life (vv. 3-7). In such a case, it would seem, there is nothing fundamentally new in the apostle's appeals. But the matter is still not quite so simple: the appeal really has remained the same, but the circumstances have changed fundamentally. Before, the call to a sanctified life sounded precisely as a call and a wish; now it sounds like a requirement. There is nothing surprising in such a change, for before the issue was righteousness in this present, still untransformed world; now the issue is the Kingdom, to which Paul calls his listeners and readers. In the untransformed world, the question of a sanctified life is above all a question of righteousness in all its fullness: sanctification presupposes the transformation of human nature, without which it is not capable of righteous life, if, of course, righteousness is understood not as formal adherence to some moral code, but as the acquisition of the inner Torah.
However, the Torah never demanded such righteousness from a person; it only offered it as an ideal toward which it called people to strive. But the ideal and the exceptional cases of our still untransformed world are, as we can see, the norm for the Kingdom, so that the apostle, following the Savior Himself, calls the faithful to a sanctified life not as to something exceptional, but as to the norm without which it is impossible to become a resident of the Kingdom. And that means it is impossible to be a Christian.